1. Background—Field of Invention
This invention pertains to electronic devices that can be used on the lap of a seated user, such as a laptop computer, and more particularly to maintaining such devices in a secure and stable condition while on the lap, and to preventing the devices from falling to the floor.
2. Background—Discussion of Prior Art
Inventors of relevant prior art have pointed to, and attempted to remedy, practical problems involved in the use of the laptop computer. For example, it has been previously noted that when a laptop computer is being used while on the lap it is at risk of slipping off the lap and falling onto the floor, being damaged as a result (e.g., Bourque, U.S. Pat. No. 5,667,114, contains a discussion of this problem; see especially paragraph 4 of Bourque's Background section). The current invention also serves to remedy practical problems associated with use of the laptop computer, as well as other electronic devices that can be used on the lap, but it differs from the prior art in important ways.
Scrutiny of prior art reveals seven specific structural and functional characteristics that frequently recur and which typically differ between the prior art and the invention disclosed in this application. Because awareness of these differentiating characteristics can help one appreciate the novelty and non-obviousness of the current invention, these characteristics will be enumerated before specific prior art patents are discussed. The seven characteristics are:
1. Prior art is designed to be used primarily, and in many cases exclusively, in a standing or walking position; in contrast, the invention being disclosed here is designed to be used by a person who is working in a seated position. As a result, the problems addressed by the prior art are frequently not the same as those addressed by the current invention.
2. Prior art generally provides a flat physical surface—such as a tray, desk, or platform—upon which the laptop computer rests; in contrast, the invention being disclosed here allows the laptop computer to rest directly on the user's lap.
3. Prior art generally includes means that transfers the weight of the laptop computer to the shoulders or other parts of the body; in contrast, the invention being disclosed here allows the weight of the laptop to be borne and carried by the lap itself.
4. Prior art establishes a predetermined and non-adjustable working distance between the laptop computer and the user, thus setting the degree to which the arms must be extended to reach the keyboard; further, the prior art maintains the computer in a square position with respect to the body, so that the left and right arms are extended equally when resting on the keyboard, but does not allow the user the option of positioning the laptop off-square (angled). In contrast, the current invention allows the user to adjust the working distance between the laptop and the user, as well as to determine whether the laptop will be square or off-square with respect to the user's body.
5. Prior art immobilizes the laptop against a specific part of the abdomen or thigh; in contrast, the invention disclosed here does not immobilize the laptop computer against a part of the body. In fact, in the invention disclosed here, the laptop can be easily moved about on the lap. This freedom of movement is inherent in the notion of a “tether.” The notion of tethering is essential to our invention and a central point of differentiation between our invention and the prior art.
6. Prior art makes use of straps and similar flexible members for the function of “support,” or to pull the laptop into direct apposition against the body of the user; in contrast, in the invention being disclosed here, flexible members function to tether the laptop in a manner that does not carry the weight of the laptop while it is in use and does not pull the laptop against the body.
7. Prior art tend to be relatively bulky, heavy, and to have one or more parts that cannot easily be folded or compressed into a small space, for transport or storage; in contrast, the invention disclosed here is small and light, with its non-compressible parts being very small and thus allowing the user to more easily fit the invention into a small space.
An awareness of these above seven characteristics can help one differentiate the invention disclosed in this application from prior art patents. These differences are apparent in the following prior art patents, which are the most relevant uncovered in a careful search:
Cobbs (U.S. Pat. No. 4,715,293) provides a “desk” to support the laptop computer, and a rigid support system with shoulder frames to transfer the weight of the laptop to the shoulders of a standing user.
Bourque (U.S. Pat. No. 5,667,114) provides a “platform” that supports the laptop computer, as well as shoulder straps that transfer the weight to the shoulders. The dimensions of the platform, which rests directly against the front of the user's body, determines the working distance between the user and the laptop computer.
Boyer et al. (U.S. Pat. No. 5,713,548), although designed to be used by a seated user and to let the weight of the laptop be carried by the lap, does not tether the laptop computer to the user, but instead provides a thick Velcro band that is wrapped around the upper legs; this Velcro band adheres to Velcro pads that are attached to the bottom of the laptop computer, the result being that the laptop computer “sticks” to the lap.
Hrusoff et al. (U.S. Pat. No. 5,724,225) provides a “tray” that supports the laptop computer, and a system of straps that transfers weight from the tray to the shoulders.
Myles et al. (U.S. Pat. No. 5,887,777) provides a shoulder strap that supports the weight of the laptop computer, for use in the standing position.
Sauer et al. (U.S. Pat. No. 5,938,096) provides a platform-like bottom panel that carries the weight of the laptop, for use in the standing position. Also included are straps to transfer weight from the panel to the shoulders, and also a waist strap that pulls the laptop against the user's body.
Piatt (U.S. Pat. No. 6,006,970), for use while standing or walking, provides both a harness and a leg, which extends to the floor, to support the weight of the laptop, and a belt mechanism that holds the laptop immobile in fixed relation to the front of the body.
Svegliato (U.S. Pat. No. 6,062,522) provides a platform-like “flat planar surface,” which is belted at a fixed distance from the user, for use with a computer “mouse.”
3. Background—Problems Addressed by the Invention
When a laptop computer rests on the lap of a seated user, there is a tendency for the laptop to slip off the user's lap or to move in other unwanted and problematic ways. First, there is a tendency for the laptop to move far forward or far to the sides, or between the user's legs, thus falling off the lap and striking the floor. In fact, many laptops are damaged by this type of fall. Second, there is a tendency for the laptop computer to slide forward on the lap so that, even without falling off the lap, it is positioned a greater distance from the user's hands, arms, and upper body than is comfortable or ergonomic. Third, there is a tendency for the laptop computer to rotate on the lap surface, in a clockwise or counter-clockwise direction, such that the laptop is not “square” with respect to the user's upper body but instead rests in such a position that the right arm and left arm must be unequally extended from the body in order to reach the keyboard of the laptop. These and other untoward movements of the laptop computer can be induced by gravity or by inadvertent body movements.
To prevent or minimize these untoward movements of the laptop computer, or to correct them once they occur, takes ongoing attention and effort by the user. For example, when a person sits with feet flat on the floor, the knees may be lower than the thighs and this creates a downward-sloping lap surface, which can cause the laptop to slide forward and fall off the lap. To correct this slope, many users attempt to elevate the knees by raising their heels off the ground, in a manner that is awkward and uncomfortable. As another example, concern about the laptop falling between the legs leads some users to pull the knees together into an awkward and uncomfortable position.
Because inadvertent movements of the leg, torso, or virtually any part of the body can cause the laptop to move or fall, the user must remain constantly vigilant against all body movements, however minor. The user is thus constrained in all physical movements, be they subtle or gross. The user necessarily exists in a condition of subtle vigilance and even stress and tension, because of concern about what will happen if attention to the disposition of the laptop is momentarily relaxed. Further, the efforts and postures undertaken to prevent the laptop from moving or falling produce in the user a state of discomfort. The user must never stand or stretch without giving careful thought to the disposition of the computer; a user who stands or stretches carelessly may eject the laptop onto the floor. The need to carefully attend to these untoward possibilities distracts the user from work being carried out on the laptop.